# 14.8, Materials: who supplies, who pays, where's the margin?
On most UK jobs, you're expected to take charge of materials and make a fair margin on them. The trick is being clear, not shy.
Who normally supplies materials?
Short version: you supply most materials, unless it's a big-ticket item the client wants to choose.
On domestic jobs, it's standard for the tradesperson to supply everything needed to do the work – fixings, pipe, cable, boards, plaster, sealants, sundries – and often the main items too (boiler, consumer unit, sanitaryware) unless the customer specifically wants to pick and pay for those themselves.
On commercial work, contractors and developers often specify brands and may procure some big items directly, but they still expect subbies to supply day‑to‑day materials and small plant and build the cost into their rates.
Typical patterns:
- Plumbers/heating engineers: usually supply everything – boilers, cylinders, valves, pipe, fittings, controls – because of compatibility, warranty and safety.
- Electricians: normally supply all cable, accessories, consumer units, fixings and sundries; clients sometimes buy decorative fittings (pendants, fancy wall lights) separately.
- Kitchen and bathroom fitters: often the client purchases the kitchen/bathroom suite from a retailer; fitter supplies all fixings, trims, ply, adhesives, sealants, and sometimes extra carcasses or panels.
- Builders/general trades: supply structural and finishing materials, unless it's a client‑supplied item (e.g. special tiles, windows, kitchen).
If the customer insists on buying everything themselves, your labour price needs to go up, because you've just given up materials margin and taken on extra hassle.
Is materials markup normal – and how much?
Yes, marking up materials is standard practice. You're not a charity or a free courier.
- UK construction and contractor pricing guides commonly talk about 10–20% markup on materials for residential work as a normal range.
- Some specialists, or jobs with a lot of risk/handling, work higher, but 10–20% is a sensible ballpark for most trades.
Remember markup is on your cost, not the shop's shelf price. If you pay £100 at the merchant and use a 20% markup, you charge £120 – the extra £20 helps cover your time ordering, collecting, storing, plus warranty risk if something fails.
You don't have to list "markup" as a separate line – most trades just show "Materials: £X" in the quote. If a customer asks, you can calmly say:
"There's a small margin on materials to cover my time sourcing, collecting and dealing with any problems. I'm not charging retail on top of retail."
Trade price vs retail – what's the gap?
You will nearly always pay less than a walk‑in retail customer at merchants if you're set up correctly.
- A basic trade card at many UK builders' merchants typically gives around 10% off standard retail prices.
- With a proper trade/credit account and regular spend, discounts on common lines (timber, plasterboard, bricks, fixings, pipe, cable) can be well above 10%, especially if you negotiate or promise repeat business.
- Price‑tracking reports from builders' merchant indices show that in 2025, merchant prices were under pressure, with average selling prices actually down slightly year‑on‑year, even while volume rose – meaning there's room to negotiate if you're giving them consistent orders.
Roughly speaking:
- DIY customer walking in and paying sticker price is at 100% retail.
- A small trade with a basic card might be paying 90–95% of that.
- A busy local builder with an account and volume might be paying 80–90% of list on common items.
That gap is where your materials margin lives. You're not "ripping them off" – you're using your trade buying power and logistics to deliver a complete job.
How different trades usually handle materials
Plumbers / heating
Norm: Supply everything – boiler, rads, valves, pipe, fittings, chemicals, filter, flue, controls.
Markup: Often 15–30% on materials because of warranty risk, returns, and all the running about.
Customer‑supplied gear: Many plumbers charge extra labour or refuse to warrant customer‑supplied boilers or sanitaryware, because if it fails, they still get called.
Electricians
Norm: Supply all cable, accessories, consumer unit, earthing, fixings; customers sometimes supply decorative fittings.
Markup: Commonly 10–20% across most materials. Higher on fiddly one‑offs and small parts.
Customer fittings: If the client supplies lighting, many sparks make it clear they're only warranting the labour, not the fitting itself.
Kitchen/bathroom fitters
Norm: Customer often buys the kitchen/bath suite; fitter supplies all fixing materials, trims, underboards, adhesives, sealants, timber, and sometimes supplementary units.
Markup: Normal on the stuff they supply (again 10–20%), and sometimes a handling fee or higher labour to fit customer‑supplied units, especially from cheaper sheds that are more work to assemble.
Builders/roofers/landscapers
Norm: Supply most of the core materials (bricks, blocks, timber, insulation, tiles, membrane, aggregates, etc.). Clients may choose finishes (tiles, flooring, paint colours) but the builder still often buys them.
Markup: Typical guide ranges talk about 10–20% on materials for residential work, with commercial packages sometimes working on tighter percentages but higher volumes.
Whatever the trade, the pattern is the same:
- You control and supply the materials that make the job work.
- You make a fair margin on them.
- You're upfront about what's included.
What to do next
- Read: 14.2 – How to price your first job without underselling yourself (includes materials markup in the formula)
- Read: 14.6 – Pricing domestic vs commercial (materials handling differs between the two)
- Read: 14.9 – How to price extras and variations without losing the customer
- Read: S16 – Writing your first quote (how to present materials in your quote clearly)
- Download: Variation confirmation email template (for when materials change mid-job)
Sources (UK)
- UK builders' merchant trade card and account terms – typical discount structures for trade customers at major UK merchants.
- BMF / GfK builders' merchant market data – merchant selling price trends, volume and pricing pressure data.
- Construction and contractor pricing guides – 10–20% materials markup as standard for residential work.
- Trade forum consensus (ScrewFix Community, MyBuilder, Electrical Direct) – real-world markup ranges and customer‑supplied materials policies by trade.
- HMRC guidance on allowable business expenses – materials as deductible business costs.
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